1. Field of the Invention
The present invention relates generally to color photography and more particularly it relates to a color diffusion transfer process. The invention further relates to an image-receiving element used for such a color diffusion transfer process.
2. Description of the Prior Art
In a color diffusion transfer process, a photosensitive element having photosensitive emulsion layers containing silver halide is imagewise exposed to form therein latent images and the latent images are developed by a processing solution to form, at the same time, an image-like distribution of color image-forming materials. Then, the image-forming materials are, at least partially, transferred to an image-receiving layer in a superposed relationship with the photosensitive element to form thereon a positive color image.
Examples of the color diffusion transfer process are the process as described in the specification of U.S. Pat. No. 2,983,606 in which developers, i.e., dyes which have the ability to develop silver halide and can develope exposed silver halides, are used as the color image-forming materials and a process as described in the specifications of U.S. Pat. Nos. 2,647,049 and 2,774,668 in which the phenomenon of the release of color image-forming materials on development of latent images with a color developing agent is utilized. The image-receiving element used in such processes is usually an opaque or transparent support having formed thereon an image-receiving layer containing a water-permeable and alkali solution-permeable polymer mordant. Examples of polymer mordants are poly-4-vinylpyridine as described in the specification of U.S. Pat. No. 3,148,061 and the various vinylic quaternary salt polymers as described in the specification of British Patent No. 1,261,925.